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AssigneeDrexelbrook Controls, Inc.
InventorsFrederick L. Maltby, Kenneth M. Loewenstern, Jack G. Benning, Jr.
Estimating the term…
A probe for the measurement of the level of conductive materials within a conductive vessel is disclosed which is particularly suitable for the measurement of the level of conductive granular materials such as coal or other minerals or plastics or vegetable matter which are conductive. In a preferred embodiment the probe comprises a conductive steel core covered with a layer of insulating plastic and covered further with a layer of a semi-conductive material which preferably comprises a plastic which has been partially filled with a conductive material such as carbon black. Other embodiments wherein the probe may comprise a conductive plate covered by insulation further covered by a similar semi-conductive layer are also disclosed. Reference is made to prior art disclosures of circuitry and theory which enable the use of the probe of the invention.
A method for measuring the level of conductive materials within a vessel comprising the steps of:
A method for measuring the level of conductive materials in a vessel, comprising the steps of installing a probe in said vessel, said probe comprising a conductive electrode, an insulative coating on said electrode preventing said electrode from contacting said conductive materials and semi-conductive coating over said insulative coating forming the external surface of said probe whereby said semi-conductive coating becomes an equipotential surface with respect to said electrode where covered by conductive materials, exposing said probe to said materials the level of which is to be measured, and measuring the capacitance between said electrode and said equipotential surface.
A method for the measurement of the level of conductive materials within a vessel comprising the steps of providing a probe comprising a probe member, an upper termination and a lower termination, said probe member comprising a conductive core covered by an insulating layer and further covered by an outermost semi-conducting layer, said conductive core being electrically insulated from said conductive materials and being electrically isolated from said vessel and provided with electrical connection to an electrical terminal adapted to be connected to sensor circuitry for providing a signal representative of the level of said conductive materials within said vessel, and measuring the capacitance between said core and that portion of said outermost layer contacted by said conductive materials.
Dependencies are inferred from the claim text.